A well known type of power drill apparatus, the drill press, is commonly used to accurately guide a drill bit through a motion range.
Most commonly available drill presses are of the type in which the drill is lowered into contact with the workpiece. Only a limited number of drill presses can perform a drilling operation on an overhead or overlying surface, that is, a surface which is only readily accessible from a position directly underneath.
Prior art inverted drill presses, while facilitating drilling operations on overlying surfaces, are often cumbersome and not readily mobile. Moreover, many of these prior art presses require the operator to be positioned close to the power drill support and thus, beneath the drilling site. Such a requirement increases the risk of injury to the operator from falling metal particles dislodged during the drilling process.
These problems are particularly significant in the context of drilling operations underneath a vehicle. More particularly, the prior art drill presses have not been well suited for use in the installation of trailer hitches or similar devices on automobile frames.
Due in part to the substantial design changes which have occurred in the automobile industry over the past decade, today's vehicles are often unable to accommodate a temporary multi-clamp hitch that would attach directly to the vehicle bumper. Therefore, the installation of a bolt-on trailer hitch, or similar device, on such late model vehicles becomes necessary. The installation of a bolt-on hitch generally requires overhead drilling, and can pose significant problems.
For instance, if a hydraulic lift is not available, the installer must use jacks or ramps for raising an end of the vehicle. In either case, the installer must be positioned beneath the partially elevated vehicle, thereby increasing the hazards associated with the installation operation. Moreover, because the elevated vehicle is at an angle relative to the floor surface, not only must the operator generate enough vertical force so that the drill bit penetrates the vehicle frame, but the power drill must be held at an angle so that the bit is perpendicular to the frame surface. Applying sufficient force at the proper angle can be awkward and poses a drill control problem for the operator.
Moreover, even if the installer has access to a standard overhead vehicle lift, the available prior art overhead drill presses require that the operator be positioned proximate the drill press during drilling. As previously mentioned, such a location increase the danger with which the drilling operation is conducted since the operator is exposed to the expelled metal fragments of the drilled vehicle frame. Furthermore, as most garage floors are sloped for drainage, the drill bit of a standard inverted drill press will not be perpendicular to the vehicle frame unless the angle of the drill press base is adjusted relative to the floor.